Ice-channel cutting attachment for ships

ABSTRACT

A ship is equipped with a skeletonized bow projecting forwardly from the hull and comprising a trussed frame from which generally parallel corrosion-resistant cables extend from an elevation above water level to the level of the bottom of the hull. In the preferred arrangement, this frame carries individually powered ice cutting saws in an array materially wider than the ship, the saws being mounted for vertical and lateral tilting adjustment responsive to automatically functioning leveling devices and equipped with semi-circular guards. The saws cut beam-like strips of ice from which the cables break off and deflect sections of an ice floe.

United States Patent 1 Abendroth Feb. 20, 1973 [54] ICE-CHANNEL CUTTING ATTACHMENT FOR SHIPS [76] Inventor: John C. Abendroth, 4238 W. Hawthorne Trace Road, Milwaukee, Wis. 53209 [22] Filed: Feb. 8, 1971 [21] Appl. No.: 113,328

[52] US. Cl ..114l42 [51] Int. Cl. ..B63b 35/08 [58] Field of Search ..1 14/40, 41, 42

[5 6] References Cited UNITED STATES PATENTS 2,883,957 4/l959 Ettinger ..1 14/42 2,551,967 5/1951 Pouliot ..l 14/42 Primary Examiner-Trygve M. Blix Attorney-Wheeler, House & Wheeler 57 I ABSTRACT A ship is equipped with a skeletonized bow projecting forwardly from the hull and comprising a trussed frame from which generally parallel corrosion-resistant cables extend from an elevation above water level to the level of the bottom of the hull. In the preferred arrangement, this frame carries individually powered ice cutting saws in an array materially wider than the ship, the saws being mounted for vertical and lateral tilting adjustment responsive to automatically functioning leveling devices and equipped with semicircular guards. The saws cut beam-like strips of ice from which the cables break off and deflect sections of an ice floe.

19 Claims, 14 Drawing Figures PATENTEDFEBZOIW 3,717,115-

SHEEIlUF 3 PATENTED M 1 3,117,115

SHEET 3 OF 3 \/m amor 70/112 6. Qfiazaroliz ICE-CHANNEL CUTTING ATTACHMENT FOR SHIPS BACKGROUND OF INVENTION Although ice cutting saws have heretofore been proposed for ice breaking ships, they have not proved successful as previously contemplated and ice breakers conventionally have been limited in practice to heavily reinforced hulls which break up an ice floe either by ramming it or by riding up onto it and breaking the ice by sheer weight of the ship hull. Ice breaking by these procedures is a slow and arduous process involving excessive power and frequently failing of its purpose due to ice thicknesses beyond the capacity of the ship. (The Military Engineer, Vol. 62, page 81) The ice breakers currently in use are specially built for the purpose and may have heavy shell plating and increased stem thickness. (Steel Ships, 9th ed., Charles Griffin & Co. Ltd., London, page 254) In the Arctic, with specific reference to the Northwest Passage, ice forms annually to a thickness of about 6 feet. Multiyear ice is as much as 11 feet thick. Pressure ridges or like irregularities may rise to a height which gives a total ice thickness of 20 feet, exclusive of snow cover. (See The Military Engineer, Vol. 62, page 82) SUMMARY OF INVENTION As distinguished from prior ice breaking ships, the instant device includes a trussed frame which can be adapted or fitted to any conventional ship hull, with or without added internal reinforcement, to project to a width materially in excess of the maximum beam of the hull. An important feature of the invention consists in the generally parallel cables which run from the trussed frame aft to points of anchorage on the ship hull and laterally outwardly therefrom. In effect, these cables constitute a skeletonized supplemental bow for the ship. Since the water passes freely between them, they do not greatly increase resistance to ship movement. Since they are flexible, they can yield individually to accommodate movements of the ice floes upon which they act. By pushing the ice blocks down and aside from the ship '5 path, they almost eliminate, with the exception of small fragments, the impact of the ice blocks with the ship bow. The channel cut by the saws will permit the ship to be maneuvered to attack the ice floes at the most vulnerable points and also to provide open space beside the ship into which, on occasion, severed ice cakes might be diverted. An incidental advantage is the fact that once such a channel has been cut through the ice, it provides an open passage for other ships which are not equipped with the saw assemblies of the instant invention, although outfitted with the structural frame and cable segment.

The trussed frame carries an array of laterally spaced saws which will subdivide into strips the ice of a floe in the path of a ship. The most widely spaced of these saws will be farther apart from the beam of the hull.

In operation, the saws are desirably in a generally triangular pattern. The beam-like ice cakes may project as much as seventy feet from their connection with the floe, thus being subject to very considerable moment arm pressure when their free ends are acted upon by the cables. Thus the cables break ofi strips from the beam-like lengths of ice and guide them downwardly and outwardly from the path of the ship.

Each saw is preferably of great diameter and fabricated in spoked sections for convenience of manufacture as well as for shipping. A 44 foot diameter is contemplated to deal with the ice conditions described. The teeth are especially designed and equipped with replaceable channels carrying cutting tools such as carbide bars or the like. Each saw is preferably housed, there being several advantages, one of which is to confine water thrown by the saw. Since the saws are heated by friction in their cutting operation, they tend to prevent the water from freezing in the housing which returns thewater to the sea. It is contemplated that heaters may be provided for the saws or the motors or other moving parts but these are not illustrated, being well-known. They would be used primarily when the saws are not in operation, the objective being to keep them in operable condition regardless of temperature.

It is important that arrangements are made for adjusting the level of the housings in accordance with changes in position of the saw. This can be done in any desired manner as, for example, by the use of the automatically self-leveling apparatus which maintains a gun platform level regardless of the movement of the ship upon which it is mounted.

It is desired, as a safety measure, to provide an automatic control which will lift from the water any saw which becomes jammed or the engine of which stops for any reason. In fact, it may be desired that all of the saws will automatically be raised in the event of any such occurrence.

Each saw is individually adjustable upwardly and downwardly and tiltably either by deck engines or fluid actuated rams.

The means for automatic control of the engines or rams is not per se a part of this invention, being wellknown. Typical means for this purpose are disclosed in Gyroscope: Theory and Design (1961) by Paul H. Savet, pages -142 and 132-133. The lack of such adjustments, however effected, is believed to be responsible for the fact that previous proposals to equip ships with ice cutting saws have not proved successful.

In the instant device, the saws are not only made up in sections but are readily repaired, even at sea. In addition to the fact that the teeth are carbide tipped, carbide bars or the like are desirably applied also along the spokes of the saw blades to prevent binding during a horizontal or transverse movement of the ship and to widen the cut for facilitating changes of direction during operation.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a fragmentary detail view in side elevation of a bow portion of a ship equipped with the invention.

FIG. 2 is a diagrammatic fragmentary plan view of the bow portion of a ship equipped with the invention.

FIG. 3 is an enlarged fragmentary detail view of one of the saw installations.

FIG. 4 is a side elevation of a slightly modified saw installation, portions of the saw guard being broken away.

FIG. 5 is a fragmentary detail view on the line 5-5 of FIG. 4.

FIG. 6 is a view taken in axial cross section through the saw and guard shown in FIG. 4.

FIG. 7 is a view similar to FIG. 4 showing a somewhat modified installation.

FIG. 8 is an enlarged fragmentary detail view of a bearing providing for tilting of the saw and guard upon a fore and aft axis.

FIG. 9 is a view in transverse section on the line 9-9 of FIG. 8.

FIG. 10 is a fragmentary detail view of a cable anchorage including a clevis and cable tensioning turnbuckle.

FIG. 1 l is a front elevation of the device as applied to the bow of a ship.

FIG. 12 is a fragmentary view in side elevation showing application of the invention to adifferent but wellknown form of ship hull.

FIG. 13 is a fragmentary view in side elevation showing a skeletonized auxiliary stern structure for protecting the propeller and rudder.

FIG. 14 is a diagrammatic view in section on the line 14-14 of FIG. 13.

The ship hull 10 may be of any appropriate design. Its bow 12 may be relatively blunt and nearly vertical but desirably has a forwardly projecting prow 16 as best shown in FIG. 1. The deck may have a beam considerably in excess of the beam of a hull portion at a lower level, FIG. 2.

Mounted on the ship at a point well above water level but below deck 15 is a trussed frame 20 which engages the hull at spaced points. For example, there is desirably a member 22 which engages the hull at its stem and other members 24 which engage opposite sides of the hull aft of the stem and still other members 26 which engage the hull further aft. If required, the hull may be internally braced as indicated in dotted lines at 28 in FIG. 2.

Guy cables such as those shown at 30 in FIG. 1 suspend the frame 20 from the ship at an appropriate level. Below the frame there are generally parallel cables 32 which not only brace the frame but perform the ice breaking and guiding function above described. These are only fragmentarily illustrated. They are anchored at their lowerends either directly to the hull, as at 34 in FIG. 1, or 35 in FIG. 12. So far as the outermost of these cables are concerned, they may be connected to arms 36 which project laterally from the hull to receive the cables as shown in FIG. 2. Cable anchorages at one end or the other, and preferably at the bow end, include a turnbuckle such as that shown at 35 (FIG. 4) for adjusting cable tension. It is important that the cables be made of corrosion-resistant materials or so coated with nylon or otherwise as to make them corrosion-resistant.

The pitch of these cables is greatest near the stem and keel. They have progressively decreasing pitch at points remote from the keel due to the fact that they I are connected farther aft. Thus they tend to force ice cubes laterally as well as downwardly. Ic'e cakes severed from the floe are forced under the ship, or into the cleared channel beside the ship, or even under laterally adjacent portions of the floe. The cables may be regarded as a skeletonized extension of the bow at minimal cost. They cause little drag to the forward motion of the ship because the water passes freely between them.

The frame 20 includes forwardly projecting structural members 40 which are laterally spaced as best shown in FIG. 2 and upon which the several saw assemblies are adjustably supported. In order that the frame itself may remain fixed with reference to the hull, the saws nevertheless being individually adjustable, support member 42 is pivoted at 44 to each of the frame members 40. The member 42 may be adjusted about its pivot by means of fluid-operated rams 46, as in FIGS. 3 and 4, or by means of a cable 48 operated by a deck engine diagrammatically illustrated at 50, as in FIG. 7.

At the end of the pivoted frame member 42 is a swivel bearing which may be of the type illustrated in FIG. 8 where a ring 54 contains bearings 56 engaged by the flange 58 of a tube 60. As indicated in FIG. 9, the tube 60 may be oscillated from side to side between the full line and dotted line positions, subject to the operation of a fluid actuated ram 62. The member 60 carries the respective saw 66 and its guard 68 and the individual saw-actuating motor 70, these parts being operable as a unit upwardly and downwardly as shown in FIG. 1 and tiltably as shown in FIG. 9. The saw guard 68 may be pivoted as in FIG. 7 for adjustment independently of the saw so that its lower margin 74 can be maintained approximately horizontal by means of fluidoperated ram 76 (FIG. 1). Heating elements (not shown) are contemplated to be used wherever necessary to maintain the parts operative during intervals when they are not in actual use.

It will be understood that each of the several saws will be mounted and preferably individually driven in the manner described.

The preferred saw construction is best shown in FIG. 4. Each saw is made up of segments 78 including spokes 79 and fastened together by plates 80. Each preferably includes relatively short teeth 82 and a notch 84 bordered by a longer tooth 86. Each tooth preferably has a replaceable channel 88 applied to its cutting surfaces and carrying carbide cutting tools at its extreme ends and also along its sides. As best shown in FIG. 4, the carbide-carrying channels 89 are also preferably applied to the leading edges of the spokes 79. The carbide carrying channels 88 and 89 have a width or axial thickness greater than the spokes 79 to provide a wide kerf.

As already indicated, I prefer that these saw blades be approximately 44 feet in diameter in order to deal with ice up to a total depth of approximately 20 feet. The ice floe 89 is supported on the water. The parallel saws shown in FIG. 2 will cut parallel beams 90 of ice which desirably will be completely severed from the rest of the floe except at their extreme ends remote from the bow of the ship. As the free rear end 92 of each such beam is encountered by the cables 32 above described, it will be forced downwardly as shown in FIG. 1 and after some deflection, it will break off as indicated at 94, thence being pushed downwardly and rearwardly as shown at 96. Some of these chunks of ice will be pushed laterally beneath adjacent portions of the floe. Others will be left in the channel which has been cut through the floe by the operation described. Although the array of cables has a generally arcuate disposition in cross section, the majority of the ice cakes 96 will pass beneath the hull. They will have little or no impact on the hull but will slide freely beneath it as the hull moves on.

It is contemplated that a similar guard desirably made of spaced cables 32' and structural supporting members 20 will protect the rudder 31 and propeller 33 from the ice both during forward motion of the ship and during possible reverse operation thereof. (FIGS. 13 and 14) I claim:

1. An ice cutting attachment for a ship bow which comprises a frame, means for supporting the frame, an array of saws laterally spaced from each other in parallel fore and aft planes, individually adjustable means for supporting the saws from the frame, and affording independent lateral tilting movement of each of said 1 saws about a fore and aft axis to maintain said saws in a vertical plane, and means for powering the saws.

2. An attachment according to claim 1 in which the laterally most remote saws in said array are spaced materially in excess of the beam of the ship upon which the frame is mounted, whereby to accommodate maneuverability of the ship in the lane cut by the saws.

3. An attachment according to claim 1 in which the upper portion of each saw is covered by a shroud for confining spray.

4. An attachment according to claim 1 in which the individually adjustable means includes a boom on which the saw is mounted and which has vertically pivotal hinged connection with the frame.

5. An attachment according to claim 4 in which the individually adjustable means for supporting the saws includes a saw mounting member on the end of the boom, said mounting member being swiveled on a fore and aft axis for lateral tilting movement with respect to the boom.

6. An ice cutting attachment according to claim 2 in which the saws are in generally triangular pattern with the central saw advanced and the other saws of said array progressively offset outwardly and rearwardly.

7. An ice cutting attachment according to claim 4 in which the several saws have individual motors for driving them.

8. An ice cutting attachment for a ship bow which comprises a frame, means for supporting the frame, an array of saws laterally spaced from each other in parallel fore and aft planes in which said saws comprise segments with radial spokes and circumferentially connected toothed peripheral portions.

9. An ice cutting attachment according to claim 8 in which the said portions have inter-tooth spaces including circumferentially spaced relatively deep slots extending toward respective spokes.

10. An ice cutting attachment according to claim 8 in which the said portions have teeth faced with replaceable channels provided with exposed ice-cutting carbide tools.

11. A ship hull provided with a bow frame, and a skeletonized bow extension for engaging and deflecting ice and comprising closely spaced cables having for- 0 ward portions anchored to the frame and aft portions anchored to said ship hull.

12. A ship hull according to claim 11 in which centrally disposed cables descend more sharply to their aft portions than the laterally disposed cables, the latter being progressively anchored farther aft as they are farther offset laterally from the centrally disposed cables.

13. A ship hull according to claim 11 in which the width of the frame and of the aft cable anchorages exceeds the hull beam.

14. A ship hull according to claim 13 having an array of transversely spaced ice cutting saws operatively mounted upon said frame, the over-all width of the array of saws being in excess of the beam of said hull, saws nearest the center of the frame being more advanced with reference to the. ship hull than saws mounted on the frame portions of maximum width, the latter being spaced apart more widely than the hull beam at saw level.

15. A ship hull according to claim 14 in which the said saws have support members pivotally connecting them to the frame for individually adjustable vertical movement.

16. A ship hull according to claim 14 in which respective saws have mounting means individually providing for up and down and tilting movement.

17. A ship hull according to claim 14 in which each saw has a guard enclosing an upper portion thereof.

18. An ice cutting attachment according to claim 8 including cutting tools on said spokes, said cutting tools having a width greater than the axial thickness of said spokes.

19. A ship hull in accordance with claim 11 wherein some of said cables are anchored to said hull beneath the water level and beneath said hull.

I =8 l l 

1. An ice cutting attachment for a ship bow which comprises a frame, means for supporting the frame, an array of saws laterally spaced from each other in parallel fore and aft planes, individually adjustable means for supporting the saws from the frame, and affording independent lateral tilting movement of each of said saws about a fore and aft axis to maintain said saws in a vertical plane, and means for powering the saws.
 1. An ice cutting attachment for a ship bow which comprises a frame, means for supporting the frame, an array of saws laterally spaced from each other in parallel fore and aft planes, individually adjustable means for supporting the saws from the frame, and affording independent lateral tilting movement of each of said saws about a fore and aft axis to maintain said saws in a vertical plane, and means for powering the saws.
 2. An attachment according to claim 1 in which the laterally most remote saws in said array are spaced materially in excess of the beam of the ship upon which the frame is mounted, whereby to accommodate maneuverability of the ship in the lane cut by the saws.
 3. An attachment according to claim 1 in which the upper portion of each saw is covered by a shroud for confining spray.
 4. An attachment according to claim 1 in which the individually adjustable means includes a boom on which the saw is mounted and which has vertically pivotal hinged connection with the frame.
 5. An attachment according to claim 4 in which the individually adjustable means for supporting the saws includes a saw mounting member on the end of the boom, said mounting member being swiveled on a fore and aft axis for lateral tilting movement with respect to the boom.
 6. An ice cutting attachment according to claim 2 in which the saws are in generally triangular pattern with the central saw advanced and the other saws of said array progressively offset outwardly and rearwardly.
 7. An ice cutting attachment according to claim 4 in which the several saws have individual motors for driving them.
 8. An ice cutting attachment for a ship bow which comprises a frame, means for supporting the frame, an array of saws laterally spaced from each other in parallel fore and aft planes in which said saws comprise segments with radial spokes and circumferentially connected toothed peripheral portions.
 9. An ice cutting attachment according to claim 8 in which the said portions have inter-tooth spaces including circumferentially spaced relatively deep slots extending toward respective spokes.
 10. An ice cutting attachment according to claim 8 in which the said portions have teeth faced with replaceable channels provided with exposed ice-cutting carbide tools.
 11. A ship hull provided with a bow frame, and a skeletonized bow extension for engaging and deflecting ice and comprising closely spaced cables having forward portions anchored to the frame and aft portions anchored to said ship hull.
 12. A ship hull according to claim 11 in which centrally disposed cables descend more sharply to their aft portions than the laterally disposed cables, the latter being progressively anchored farther aft as they are farther offset laterally from the centrally disposed cables.
 13. A ship hull according to claim 11 in which the width of the frame and of the aft cable anchorages exceeds the hull beam.
 14. A ship hull according to claim 13 having an array of transversely spaced ice cutting saws operatively mounted upon said frame, the over-all width of the array of saws being in excess of the beam of said hull, saws nearest the center of the frame being more advanced with reference to the ship hull than saws mounted on the frame portions of maximum width, the latter being spaced apart more widely than the hull beam at saw level.
 15. A ship hull according to claim 14 in which the said saws have support members pivotally connecting them to the frame for individually adjustable vertical movement.
 16. A ship hull according to claim 14 in which respective saws have mounting means individually providing for up and down and tilting movement.
 17. A ship hull according to claim 14 in which each saw has a guard enclosing an upper portion thereof.
 18. An ice cutting attachment according to claim 8 including cutting tools on said spokes, said cutting tools having a width greater than the axial thickness of said spokes. 